1. Field of the Invention
The present invention relates generally to methods and apparatus for combusting particulated solids, and more particularly, but not by way of limitation, to methods and apparatus for combusting particulated solids which form tacky or molten ash at or near the combustion temperature.
2. Description of the Prior Art
A great variety of methods and apparatus for combusting particulated solids have been developed and utilized heretofore. However, in the combustion of particulated solids which form a tacky or molten ash at or near the combustion temperature, elaborate apparatus has heretofore been required and problems involving the precipitation and buildup of the ash produced on the internal surfaces of the apparatus have been encountered.
Examples of solid materials which produce a tacky or molten ash when combusted are seed and nut hulls, husks and chaff, sawdust, dried sewage sludge, etc. Such materials, for example rice hulls, have little utility other than being used as fuel and are available in large quantities. However, as mentioned above, because the materials form a tacky or molten ash when combusted, heretofore utilized combustion apparatus has been expensive and has not overcome problems associated with the precipitation and/or adherence of the ash to equipment surfaces.
By the present invention, improved methods and apparatus for combusting ash producing solids such as particulated rice hulls are provided which are simple and inexpensive as compared to prior art methods and apparatus and which obviate problems associated with the production of a tacky or molten ash.